JP3935853B2 - Fermented milk and method for producing the same - Google Patents

Description

【００２３】
本発明の発酵乳は上記範囲内でホエー蛋白質とホエーペプチドを配合するものであるが、その無脂乳固形分は８.５〜１０.５％、好ましくは９〜１０％のものが風味の点から好ましい。
【００２４】
本発明の発酵乳の調製は、発酵乳原料にホエー蛋白質と乳ペプチドとを加える以外は定法に従って行えばよく、その一例を示せば以下の通りである。
【００２５】
まず、牛乳、脱脂乳、脱脂粉乳、全粉乳、バター、クリーム等の混合加水物等などを含む発酵乳原料液を用意し、これに、所定量のホエー蛋白質と乳ペプチドとを添加する。次いで９０〜９８℃で２分〜１時間程度加熱保持し、１０〜１５ＭＰａで均質化する。更に、これをプレート式殺菌機を用いて１００〜１２０℃で３秒間殺菌し、３０〜４０℃まで冷却した後、乳酸菌あるいはビフィズス菌をスターターとして添加し、培養装置中で３０〜４０℃で５〜８時間発酵させる。最後にこれを１０℃まで冷却することで本発明の発酵乳を得ることができる。
【００２６】
この発酵乳を製造するために使用される乳酸菌あるいはビフィズス菌は特に限定されず、例えば、ラクトバチルス・カゼイ、ラクトバチルス・マリ、ラクトバチルス・アシドフィルス、ラクトバチルス・デルブルッキー サブスピーシーズ.ブルガリカス、ラクトバチルス・ヘルベティカス等のラクトバチルス属細菌、ストレプトコッカス・サーモフィルス等のストレプトコッカス属細菌、ラクトコッカス・ラクチス サブスピーシーズ.ラクチス、ラクトコッカス・ラクチス サブスピーシーズ.クレモリス等のラクトコッカス属細菌、エンテロコッカス・フェカーリス等のエンテロコッカス属細菌等の乳酸菌あるいは、ビフィドバクテリウム・ブレーベ、ビフィドバクテリウム・ビフィダム、ビフィドバクテリウム・ロンガム等のビフィドバクテリウム属細菌等のビフィズス菌が挙げられ、これらは単独あるいは併用して使用することができる。
【００２７】
また、本発明の発酵乳の製造に当たっては、発酵乳原料液中にまたは製造の適当な段階で任意成分を添加することができる。この任意成分としては、シロップ等の甘味料の他、それ以外の各種食品素材、例えば、各種糖質や乳脂肪、乳化剤、酸味料、果汁等が挙げることができる。具体的には、ショ糖、異性化糖、グルコース、フルクトース、パラチノース、トレハロース、ラクトース、キシロース、麦芽糖、オリゴ糖等の糖類、ソルビトール、キシリトール、エリスリトール、ラクチトール、パラチニット、還元水あめ、還元麦芽糖水あめ等の糖アルコール、クリーム、バター等の乳脂肪、ショ糖脂肪酸エステル、グリセリン糖脂肪酸エステル、レシチン等の乳化剤、クエン酸、乳酸、酢酸、リンゴ酸、酒石酸、グルコン酸等の酸味料が挙げられる。その他にも、ビタミンＡ、ビタミンＢ類、ビタミンＣ、ビタミンＥ等のビタミン類やカルシウム、鉄、亜鉛等のミネラル類を配合することができる。
【００２８】
以上のようにして得られた発酵乳は、安定剤として寒天やゼラチンを使用していないにもかかわらず、それらの安定剤と同等の安定なヨーグルト組織を形成し、高い保形性と滑らかな食感を有しており、特に搬送時等の振動によるカードの崩れが少ない発酵乳である。
【００２９】
従って、本発明の発酵乳は、プレーンヨーグルトや果汁・果肉入り固型ヨーグルト等のハード（固形）タイプの発酵乳として広く使用できるものである。
【００３０】
【作用】
本発明において、発酵乳原料中に熱凝固性を有するホエー蛋白質とホエーペプチドを併用添加することにより、優れた保形性を有するとともに脆さの少ない、かつ滑らかな食感を有したハードヨーグルトが得られる理由は定かではないが、以下のような作用が関与していると考えられる。
【００３１】
通常、ホエー蛋白質は、加熱処理を行うと、蛋白質の変性が生じ、静電的な反発力と疎水性相互作用を有する鎖状のタンパク質分子が広がったネットワーク構造を形成する。この構造は、疎水性が高いため、他の食品素材の影響を受けやすく、且つ塩の添加等によって静電的な反発力を失い会合しやすい状態となる。
一般に使用される発酵乳の原料は、牛乳、脱脂乳、脱脂粉乳、全粉乳等があるが、これらのいずれにもカルシウムイオン等の塩が含まれており、ｐＨ低下に伴いホエー蛋白質の静電的な反発力が失われ、これら乳成分やホエー蛋白質同士と会合しやすくなる。その結果、これら乳成分とホエー蛋白質またはホエー蛋白質同士が複雑に絡み合った状態、すなわちゲル状を形成し、ゼラチンや寒天等の安定剤（ゲル化剤）を添加したときと同等の安定化作用を発現させる。
【００３２】
このようにして得られるゲル状態は、その組織が緻密に改善されたものであるが本発明においては、併用添加される分子の小さいホエーペプチドが、このように緻密に組織化されたゲル状態の隙間に入り込み、緻密な組織を破壊することなく、凝固性を緩和し、適度な弾力性と滑らかな食感をもたらすものと考えられる。
【００３３】
【実施例】
以下、実施例を挙げて本発明を更に詳細に説明するが、本発明はこれらに限定されるものではない。
【００３４】
参 考 例 １
ホエー蛋白質の添加量と硬さの関係：
脱脂粉乳、クリーム、トータルミルクプロテイン（ＴＭＰ）（Nutrilac YO-8113：アーラーフーズ イングレディンツ ジャパン（株）製）、ホエーペプチド（W800：森永乳業社製、分子量の２０％以上が１０,０００〜５０,０００の範囲にあるもの）、ホエー蛋白質（ＷＰＩ）（アラセン８９５：ニュージーランド デイリーボード社製）を表１の配合で混合溶解したものを原料液とした。
【００３５】
これらの原料液を９０〜９５℃、約５分間加熱保持した後、１５ＭＰａで均質化し、１１５℃で３秒間殺菌後、３７℃まで冷却した。これに乳酸菌スターターとしてラクトバチルス・デルブルッキー サブスピーシーズ.ブルガリカス（Lactobacillus debrueckii ss. bulgaricus）ＹＩＴ０４４６ を１.０％（ｖ／ｖ）、ストレプトコッカス サーモフィラス（Streptococcus thermophilus）ＹＩＴ２０２１を０.５％（ｖ／ｖ）接種し、混合後、容器に充填し、３７℃の発酵室で５〜６時間発酵を行った。その後、１０℃以下まで冷却し、無脂乳固形分９.５％のヨーグルトを得た。
【００３６】
それぞれのヨーグルトについて下記の条件でレオメーター（本体：ＳＵＮ ＲＨＥＯ ＭＥＴＥＲ ＭＯＤＥＬ ＣＲ−１５０、検出部：ＳＵＮ ＲＨＥＯ ＭＥＴＥＲ ＭＯＤＥＬ ＣＲ−２００Ｄ、ヨーグルトのカード測定用プランジャー（いずれもサン科学社製）を用いて硬さ（圧縮降伏強さ）を測定した。その結果も表１に示した。
【００３７】
【表１】

【００３８】
＜ 測 定 条 件＞
ＴＡＢＬＥ ＳＰＥＥＤ ： ７５ ｍｍ／ｍｉｎ
ＲＡＮＧＥ ： ５００ｍＶ
測定温度 ： ５〜６℃
圧縮距離 ： ３０ｍｍ（歪み；６７％）
＊ 試験に際しては、応力が生じてから（プランジャーとヨーグルトが接してから）応力の測定を開始した。
【００３９】
表１より、ホエー蛋白質の添加量の増加に伴って、硬さ（圧縮降伏強さ）の値が大きくなっていることがわかった。
【００４０】
実 施 例 １
ヨーグルトの調製（１）：
脱脂粉乳、クリーム、トータルミルクプロテイン（ＴＭＰ）、ホエーペプチド、ホエー蛋白質（ＷＰＩ）を表２の配合で混合溶解したものを原料液とした。
【００４１】
これらの原料液を９０〜９５℃で約５分間加熱保持した後、１５ＭＰａで均質化し、１１５℃で３秒間殺菌後、３７℃まで冷却した。これに乳酸菌スターターとしてラクトバチルス・デルブルッキー サブスピーシーズ.ブルガリカス ＹＩＴ０４４６ を１.０％（ｖ／ｖ）、ストレプトコッカス サーモフィラス ＹＩＴ２０２１を０.５％（ｖ／ｖ）接種し、混合後、容器に充填し、３７℃の発酵室で５〜６時間発酵を行った。その後、１０℃以下まで冷却し、無脂乳固形分９.５％のヨーグルトを得た。
【００４２】
このようにして得られたヨーグルトについて参考例１と同様に硬さ（圧縮降伏強さ）と脆さを測定した。その結果を図１に示した。また、図１から算出した硬さおよび脆さの値を表２に示した。
【００４３】
【表２】

【００４４】
表２より発明品１は比較品１よりも硬さが高い値を示すことがわかった。また、図１の荷重−変位量曲線から、発明品１は比較品２に比べ脆さのないヨーグルトであることがわかった。
【００４５】
実 施 例 ２
ヨーグルトの調製（２）：
表３の配合の原料液を用いて、実施例１と同様の方法で無脂乳固形分９.５％のヨーグルトを得た。これら得られたヨーグルトについて参考例１と同様に硬さ（圧縮降伏強さ）と脆さを測定した。その結果を図２に示した。また、図２から算出した硬さおよび脆さの値を表３に示した。
【００４６】
【表３】

【００４７】
表３より、発明品２〜５の硬さの値は、１.０〜１.８Ｎの範囲内にあり、比較品１よりも硬さで高い値を示すことがわかった。一方、図２の荷重−変位量曲線から、発明品８〜１１は比較品３よりも得られた製品に脆さがないことがわかった。
【００４８】
実 施 例 ３
ヨーグルトの調製（３）：
実施例１の原料液に、ホエーペプチド（以下、単に「ペプチド」ということもある）とホエー蛋白質（ＷＰＩ）の濃度を表４に示す配合で添加して実施例１と同様の方法で無脂乳固形分９.５％のヨーグルトを得た。これらの得られたヨーグルトについて参考例１と同様に硬さ（圧縮降伏強さ）と脆さを算出した結果を表５に示した。また、それぞれのヨーグルトの官能面における評価を自由描写と表６の評価基準に基づいて評価した結果を表７に示した。更に、ヨーグルトの官能面における評価とホエーペプチド、ＷＰＩ濃度との関係を図３に示した。また更に、ヨーグルトの官能面における評価と、硬さおよび脆さとの関係を図４に示した。
【００４９】
【表４】

【００５０】
【表５】

【００５１】
【表６】

【００５２】
【表７】

【００５３】
以上の結果より、本発明の高い保形性と滑らかな食感を有するヨーグルトは、硬さが１.０〜１.８Ｎで脆さが０.１Ｎ未満にあるものが好ましく、特に硬さが１.０〜１.６Ｎ、脆さが０.０９Ｎ以下であるものが好ましいことがわかった。
また、上記硬さと脆さを有するヨーグルトは、ＷＰＩを０.０５〜１.０％、好ましくは０.１〜０.８％、ホエーペプチドを０.１〜１.０％、好ましくは０.２〜０.８％にあるものが好ましいことがわかった。更に、本発明のヨーグルトは下式（２）で示される硬さ（圧縮降伏強さ）と脆さの関係を有することもわかった。
【００５４】
【式２】

【００５５】
【発明の効果】
本発明は、発酵乳製造にホエー蛋白質を使用した場合に、更にホエーペプチドを併用添加することによって、通常の安定剤を添加した発酵乳に比べて、高い保形性と滑らかな食感を有する発酵乳を得ることができる。
【００５６】
従って、本発明の発酵乳は、食感が優れていると同時に製品の搬送時等の揺れによるカードの崩れを防ぐことができるものであり、商品的に価値の高いものである。
【図面の簡単な説明】
【図１】 図１は、実施例１で調製したヨーグルトの荷重−変位量曲線を示す図面である（Ａ：圧縮降伏強さ、Ｂ：下部降点）。
【図２】 図２は、実施例２で調製したヨーグルトの荷重−変位量曲線を示す図面である。
【図３】 図３は、実施例３で調製したヨーグルトの官能面における評価とホエーペプチド、ＷＰＩ濃度との関係を示す図面である。
【図４】 図４は、実施例３で調製したヨーグルトの官能面における評価と硬さ、脆さとの関係を示す図面である。
以 上[0001]
BACKGROUND OF THE INVENTION
The present invention relates to fermented milk having shape retention suitable for distribution and a smooth texture, and a method for producing the same.
[0002]
[Prior art]
Fermented milk (yogurt) is usually obtained by inoculating a raw material milk with lactic acid bacteria and fermenting, and its shape is classified into hard yogurt, drink yogurt, and soft yogurt. Usually, in these yogurts, various stabilizers (gelling agents) are used as additives in order to improve the texture and flavor. Commonly used stabilizers include gelatin, agar and pectin, which contribute to the stabilization of yogurt tissue.
[0003]
In particular, in hard yogurt, added gelatin, agar, etc. contribute to the texture and at the same time play a role in strengthening and modifying the curd and preventing whey separation. However, gelatin and agar have the property of gelling at a low temperature because of their low freezing point, and there is a problem that it is difficult to manage temperature and mixing methods during production. In addition, problems such as a decrease in the flavor of yogurt due to the addition of these have been pointed out.
[0004]
Furthermore, yogurt to which stabilizers such as gelatin and agar are added has good viscoelasticity, but tends to soften due to temperature changes, or has sufficient hardness, but the tissue is brittle and easily collapses. There was a problem with the texture of the resulting product. Therefore, stabilizers such as gelatin and agar are not necessarily preferable additives for the production of yogurt.
[0005]
Therefore, recently, many examples of using milk protein which is a component derived from natural milk as a stabilizer for yogurt have been seen. Milk proteins generally used as stabilizers are known to be total milk protein (TMP), whey protein concentrate (WPC), and whey protein isolate (WPI). It has been reported that it has a role to prevent water separation (whey off) during storage (see, for example, Patent Documents 1 and 2).
[0006]
However, according to the results of experiments conducted by the present inventors, it is necessary to add a large amount of whey protein (WPC or WPI) as a stabilizer to raw material milk in order to obtain sufficient hardness for the purpose of maintaining the shape during distribution. In some cases, however, the formed card becomes too hard, the gel structure becomes rough, and the flavor (texture) is significantly reduced.
[0007]
As a method for solving these problems, a method for producing a whey protein having no new heat coagulation property or partial heat denaturation properties and utilizing it as a stabilizer for yogurt has been proposed. It is necessary to carry out a separate process for whey protein (WPC or WPI) that is usually used during production, and there are still problems in workability and work efficiency, and at the same time, the card brittleness has been sufficiently improved. No, for example (see Patent Document 3).
[0008]
[Patent Document 1]
JP-A-1-196254 [Patent Document 2]
JP-A-3-198738 [Patent Document 3]
Japanese Patent Laid-Open No. 3-52940
[Problems to be solved by the invention]
Accordingly, there is a need for fermented milk having excellent shape retention, smooth flavor (texture), and less curdness of the curd, and the present invention provides such fermented milk as its subject. To do.
[0010]
[Means for Solving the Problems]
As a result of diligent research to solve the above-mentioned problems, the present inventors added a whey protein and a milk peptide in combination to a fermented milk raw material liquid, and lactic acid fermented them to provide excellent shape retention. It was found that fermented milk having a smooth texture with little brittleness was obtained, and the present invention was completed.
[0011]
That is, the present invention provides a fermented milk comprising a whey protein having heat coagulation properties and a milk peptide.
[0012]
The present invention also includes a step of adding a heat-coagulating whey protein and a milk peptide to a fermented milk raw material liquid, and maintaining the mixture by heating, and a step of homogenizing and sterilizing and cooling and then inoculating and inoculating lactic acid bacteria. It provides the manufacturing method of fermented milk characterized by including this.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
The whey protein having thermocoagulability (hereinafter abbreviated as “whey protein”) added to the fermented milk of the present invention is thermocoagulable, that is, a whey protein having a property that molecules are aggregated by heat treatment. It is. Examples of these whey proteins include whey protein, whey protein concentrate (hereinafter referred to as “WPC”) or whey protein isolate (hereinafter referred to as “WPI”), which are by-products in the production of cheese and casein. Can do.
[0014]
WPC and WPI are obtained by different processing steps starting from whey. These are abundant and have different properties and properties. However, WPI is generally not heat-treated in the treatment process, and is known to have better heat coagulation properties than other whey proteins. Yes. In the present invention, any of these may be used, and is not particularly limited. However, WPI having excellent heat coagulation properties, for example, 90% or more protein by heat treatment at 90 to 100 ° C. for 90 seconds. Those having a property that the components are thermally denatured (thermal aggregation) are preferred.
[0015]
Is added to the fermented milk of the present invention, the molecular weight of those of more than 20% which is the other component 10, 000-50, and milk peptide in the range of 000 W-800 (trade name: manufactured by Morinaga Milk Industry Co., Ltd.) , and the this compound are those of the milk protein is a component derived from natural milk amino acids were decomposed to at least a few bound molecules. More specifically, whey peptides obtained by hydrolyzing milk proteins such as whey (whey protein) and casein with an enzyme such as proteinase, and filtering and sterilizing the filtrate obtained by drying the protein. And casein peptides. As this milk peptide, it is desirable to use a whey peptide because it can improve the flavor and give a good texture.
[0016]
This whey peptide is obtained by treating whey protein, which is a by-product in producing cheese and casein, by the above method. These are abundant in variety, each with different properties and properties. In the present invention, any of these may be used, but is not particularly limited, but those having a small molecular size are preferred, and more than 20% of the molecular weight is particularly 200 to 50,000, preferably 10,000 to Preference is given to using whey peptides in the range of 50,000. Moreover, since the amino acid molecule produced in the hydrolysis step of milk protein has a unique flavor, those containing as little as possible are preferable.
[0017]
The mixing ratio of whey protein and milk peptide in the present invention is not particularly limited, but whey protein has a tendency that the card value increases (hardness increases) in proportion to the amount added, and milk peptide. Tends to weaken the card formation in proportion to the amount added. For this reason, when adding these to fermented milk, it is necessary to mix | blend and add in consideration of the cohesive force of whey protein and the fall rate of the card tension value by the addition amount of whey peptides.
[0018]
In the present invention, considering the production cost, the degree to which the fermented milk has an appropriate hardness, that is, the hardness (compression yield strength) is 1.0 to 1.8 N, preferably 1.0 to 1.6 N. The fermented milk raw material liquid may be appropriately blended with whey protein and milk peptide so that the brittleness is less than 0.1, preferably 0.09 N or less. Specifically, for example, whey protein is 0.05 to 1.0% by mass (hereinafter simply referred to as “%”), preferably 0.1 to 0.8%, and whey peptide is contained in the fermented milk raw material liquid. It is preferable to add 0.1 to 1.0%, preferably 0.2 to 0.8%.
[0019]
In addition, even if the hardness of fermented milk is in the range of 1.0 to 1.8 N, if the brittleness of the curd is 0.1 N or more by addition of the milk peptide, yogurt with excellent shape retention However, since there is no smoothness, it is not preferable in terms of flavor preference.
[0020]
Here, the hardness means the compressive yield strength, and indicates the load value at the point when the peak (maximum value) is first reached after the load value starts to rise. Although the numerical value of the hardness varies depending on the measurement method, in the present invention, a rheometer (main body: SUN RHEO METER MODEL CR-150, detection unit: SUN RHEO METER MODEL CR-200D, a yogurt card measurement plunger The values measured using (San Kagaku Co., Ltd.) are used.
[0021]
The “brittleness” is calculated from the following equation (1).
[0022]
[Formula 1]

[0023]
The fermented milk of the present invention contains whey protein and whey peptide within the above range, but the non-fat milk solid content is 8.5 to 10.5%, preferably 9 to 10%. It is preferable from the point.
[0024]
Preparation of the fermented milk of the present invention may be carried out according to a conventional method except that whey protein and milk peptide are added to the raw material for fermented milk, and an example thereof is as follows.
[0025]
First, a fermented milk raw material liquid containing milk, skim milk, skim milk powder, whole milk powder, butter, a mixed hydrolyzate such as cream, etc. is prepared, and a predetermined amount of whey protein and milk peptide are added thereto. Next, it is heated and held at 90 to 98 ° C. for about 2 minutes to 1 hour, and homogenized at 10 to 15 MPa. Further, this was sterilized at 100 to 120 ° C. for 3 seconds using a plate type sterilizer, cooled to 30 to 40 ° C., lactic acid bacteria or bifidobacteria were added as starters, and 5 to 30 ° C. in a culture apparatus. Ferment for ~ 8 hours. Finally, the fermented milk of this invention can be obtained by cooling this to 10 degreeC.
[0026]
Lactic acid bacteria or bifidobacteria used to produce this fermented milk are not particularly limited, and for example, Lactobacillus casei, Lactobacillus mari, Lactobacillus acidophilus, Lactobacillus delbruecki subspecies.Bulgaricus, lacto Lactobacillus bacteria such as Bacillus helveticus, Streptococcus bacteria such as Streptococcus thermophilus, Lactococcus lactis subspices.Lactis, Lactococcus lactis subspecies. Lactic acid bacteria such as genus bacteria or Bifidobacteria such as Bifidobacterium breve, Bifidobacterium bifidum, Bifidobacterium longum Bifidobacteria such as Um bacteria and the like, which may be used alone or in combination.
[0027]
In producing the fermented milk of the present invention, optional components can be added to the fermented milk raw material liquid or at an appropriate stage of production. As this optional component, in addition to sweeteners such as syrup, various other food materials such as various sugars, milk fat, emulsifier, acidulant, fruit juice and the like can be mentioned. Specifically, sugars such as sucrose, isomerized sugar, glucose, fructose, palatinose, trehalose, lactose, xylose, maltose, oligosaccharide, sorbitol, xylitol, erythritol, lactitol, palatinit, reduced syrup, reduced malt syrup, etc. Examples include milk fats such as sugar alcohol, cream and butter, emulsifiers such as sucrose fatty acid ester, glycerin sugar fatty acid ester and lecithin, and acidulants such as citric acid, lactic acid, acetic acid, malic acid, tartaric acid and gluconic acid. In addition, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E, and minerals such as calcium, iron, and zinc can be blended.
[0028]
Although fermented milk obtained as described above does not use agar or gelatin as a stabilizer, it forms a stable yogurt structure equivalent to those stabilizers, and has high shape retention and smoothness. It is a fermented milk that has a texture and is less likely to collapse the card due to vibration during transportation.
[0029]
Therefore, the fermented milk of the present invention can be widely used as hard (solid) type fermented milk such as plain yogurt and solid yogurt containing fruit juice and pulp.
[0030]
[Action]
In the present invention, by adding a whey protein and a whey peptide having thermocoagulability in a fermented milk raw material in combination, a hard yoghurt having excellent shape retention, less brittleness, and smooth texture is obtained. Although the reason for obtaining it is not clear, it is considered that the following actions are involved.
[0031]
Usually, when heat treatment is performed on a whey protein, the protein is denatured to form a network structure in which chain protein molecules having electrostatic repulsive force and hydrophobic interaction are spread. Since this structure is highly hydrophobic, it is easily affected by other food materials, and loses its electrostatic repulsive force due to the addition of salt or the like, and is likely to be associated.
Commonly used raw materials for fermented milk include cow's milk, skim milk, skim milk powder, whole milk powder, etc., all of which contain salts such as calcium ions. The repulsive force is lost and it becomes easy to associate with these milk components and whey proteins. As a result, these milk components and whey protein or whey proteins are intertwined in a complex state, that is, a gel is formed, and the same stabilizing action as when a stabilizer (gelator) such as gelatin or agar is added. To express.
[0032]
In this way, the gel state obtained in this way has a densely improved structure, but in the present invention, the whey peptide with a small molecule added in combination is in such a tightly organized gel state. It is thought that the coagulation is eased without entering the gaps and destroying the dense structure, resulting in moderate elasticity and a smooth texture.
[0033]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated further in detail, this invention is not limited to these.
[0034]
Reference example 1
Relationship between added amount of whey protein and hardness:
Non-fat dry milk, cream, total milk protein (TMP) (Nutrilac YO-8113: Aller Foods Ingredz Japan Co., Ltd.), whey peptide (W800: Morinaga Milk Industry Co., Ltd., 20% or more of molecular weight is 10,000-50, 000) and whey protein (WPI) (Arasene 895: manufactured by New Zealand Daily Board) were mixed and dissolved in the composition shown in Table 1 as a raw material solution.
[0035]
These raw material solutions were heated and held at 90 to 95 ° C. for about 5 minutes, homogenized at 15 MPa, sterilized at 115 ° C. for 3 seconds, and then cooled to 37 ° C. Lactobacillus debrueckii ss. Bulgaricus YIT0446 is 1.0% (v / v) and Streptococcus thermophilus (Streptococcus thermophilus) YIT2021 is 0.5% (v / v). ) After inoculation and mixing, the container was filled and fermented in a fermentation chamber at 37 ° C. for 5 to 6 hours. Then, it cooled to 10 degrees C or less, and obtained yoghurt of nonfat milk solid content 9.5%.
[0036]
For each yogurt, using a rheometer (main body: SUN RHEO METER MODEL CR-150, detector: SUN RHEO METER MODEL CR-200D, a yogurt card measurement plunger (both manufactured by Sun Kagaku) The hardness (compression yield strength) was measured and the results are also shown in Table 1.
[0037]
[Table 1]

[0038]
<Measurement conditions>
TABLE SPEED: 75 mm / min
RANGE: 500mV
Measurement temperature: 5-6 ° C
Compression distance: 30 mm (distortion; 67%)
* During the test, the stress measurement was started after the stress was generated (after the plunger and the yogurt were in contact).
[0039]
From Table 1, it was found that the value of hardness (compression yield strength) increased with an increase in the amount of whey protein added.
[0040]
Example 1
Preparation of yogurt (1):
Non-fat dry milk, cream, total milk protein (TMP), whey peptide, whey protein (WPI) mixed and dissolved in the composition shown in Table 2 were used as a raw material solution.
[0041]
These raw material liquids were heated and held at 90 to 95 ° C. for about 5 minutes, homogenized at 15 MPa, sterilized at 115 ° C. for 3 seconds, and then cooled to 37 ° C. This was inoculated with 1.0% (v / v) Lactobacillus delbruecki subspecies Bulgaricus YIT0446 and 0.5% (v / v) Streptococcus thermophilus YIT2021 as a lactic acid bacteria starter, mixed, and filled into a container. Fermentation was carried out in a fermentation chamber at 37 ° C. for 5 to 6 hours. Then, it cooled to 10 degrees C or less, and obtained yoghurt of nonfat milk solid content 9.5%.
[0042]
The yogurt thus obtained was measured for hardness (compression yield strength) and brittleness in the same manner as in Reference Example 1. The results are shown in FIG. The hardness and brittleness values calculated from FIG. 1 are shown in Table 2.
[0043]
[Table 2]

[0044]
From Table 2, it was found that Invention 1 showed a higher hardness than Comparative Product 1. Further, from the load-displacement amount curve of FIG. 1, it was found that the inventive product 1 is a yogurt that is less brittle than the comparative product 2.
[0045]
Example 2
Preparation of yogurt (2):
A yogurt with a non-fat milk solid content of 9.5% was obtained in the same manner as in Example 1 using the raw material liquid having the composition shown in Table 3. The hardness (compression yield strength) and brittleness of these obtained yogurts were measured in the same manner as in Reference Example 1. The results are shown in FIG. Table 3 shows the hardness and brittleness values calculated from FIG.
[0046]
[Table 3]

[0047]
From Table 3, it was found that the hardness values of the inventive products 2 to 5 are in the range of 1.0 to 1.8 N, and the hardness value is higher than that of the comparative product 1. On the other hand, from the load-displacement amount curve in FIG. 2, it was found that the products of Inventions 8 to 11 were less brittle than the product of Comparative Product 3.
[0048]
Example 3
Preparation of yogurt (3):
In the same manner as in Example 1, the whey peptide (hereinafter sometimes simply referred to as “peptide”) and whey protein (WPI) concentrations were added to the raw material solution of Example 1 in the formulation shown in Table 4. A yogurt with a milk solid content of 9.5% was obtained. Table 5 shows the results of calculating the hardness (compression yield strength) and brittleness of these obtained yogurts in the same manner as in Reference Example 1. In addition, Table 7 shows the results of the evaluation on the sensory side of each yogurt based on the free description and the evaluation criteria shown in Table 6. Further, FIG. 3 shows the relationship between the sensory evaluation of yogurt and the whey peptide and WPI concentrations. Further, FIG. 4 shows the relationship between the evaluation on the functional surface of yogurt and the hardness and brittleness.
[0049]
[Table 4]

[0050]
[Table 5]

[0051]
[Table 6]

[0052]
[Table 7]

[0053]
From the above results, the yogurt having high shape retention and smooth texture according to the present invention preferably has a hardness of 1.0 to 1.8 N and a brittleness of less than 0.1 N, and particularly has a hardness. It turned out that what is 1.0-1.6N and brittleness is 0.09N or less is preferable.
The yogurt having hardness and brittleness has a WPI of 0.05 to 1.0%, preferably 0.1 to 0.8%, and a whey peptide of 0.1 to 1.0%, preferably 0.5. It has been found that the content of 2 to 0.8% is preferable. Furthermore, it was also found that the yogurt of the present invention has a relationship between hardness (compression yield strength) and brittleness represented by the following formula (2).
[0054]
[Formula 2]

[0055]
【The invention's effect】
When whey protein is used in the production of fermented milk, the present invention has higher shape retention and smooth texture than fermented milk to which ordinary stabilizers are added by further adding a whey peptide. Fermented milk can be obtained.
[0056]
Therefore, the fermented milk of the present invention is excellent in texture and can prevent the card from collapsing due to shaking at the time of transporting the product, etc., and has high commercial value.
[Brief description of the drawings]
FIG. 1 is a drawing showing a load-displacement curve of yogurt prepared in Example 1 (A: compression yield strength, B: lower yield point).
FIG. 2 is a view showing a load-displacement curve of yogurt prepared in Example 2. FIG.
FIG. 3 is a drawing showing the relationship between the sensory evaluation of yogurt prepared in Example 3 and whey peptide and WPI concentrations.
4 is a drawing showing the relationship between the evaluation on the functional surface of yogurt prepared in Example 3 and the hardness and brittleness. FIG.
more than

Claims (3)

The whey protein having a heat coagulable zero. 1 and 0. 8 mass%, molecular weight of 20% or more of 10, 000 to 50, the milk peptide in the range of 000 0.2-0. 8 wt% The content of these whey proteins (X mass%) and the content of milk peptides (Y mass%) are the following conditional expressions (a) to (d),
(A) 0. 1 ≦ X ≦ 0. 0 when 2. 2 ≦ Y ≦ 2X + 0. 2,
(B) 0. 2 ≦ X ≦ 0. 0 when 4. 2 ≦ Y ≦ X + 0. 4,
(C) 0. 4 ≦ X ≦ 0. X-0 when 6. 2 ≦ Y ≦ 0. 8,
(D) 0. 6 ≦ X ≦ 0. X ≦ Y ≦ 0 when of eight. 8
Hard type fermented milk characterized by satisfying   The fermented milk according to claim 1, wherein the whey protein having thermocoagulability is a whey protein isolate or a whey protein concentrate.   The fermented milk according to claim 1 or 2, which has a hardness of 1.0 to 1.8 N and a brittleness of less than 0.1 N.

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